A Lean Approach to Designing Medical Drug Delivery Systems

At Forefront Medical Technology, a specialty contract manufacturer with a focus in disposable diagnostic, drug infusion, and medical device systems, a number of design spins and tooling iterations are key performance indicators (KPIs) for the design team. The team embraces Lean manufacturing principles not only in terms of design for manufacturability (DFM) best practices, but also in terms of eliminating non-value added activity from its overall process, thereby shortening the product development cycle.

The team also focuses on both business and technical issues in determining the best path to commercialization, and evaluates the end market perspective of new products once the products are in the field as part of its continuous improvement process. Using this approach over the past three years, Forefront's engineering team has introduced nine new products in product development cycles that averaged eight-to-nine months. Materials expertise, in-house rapid prototyping capability, and in-house tooling fabrication capabilities are key factors in achieving this speed.

For example, a recent development project involved a drug infusion dosing pump. In this instance, the development cycle was completed within five months. The customer wanted a full device with a silicone part capable of dispensing the perfect dose. From a technical design perspective the focus was on flow rate and the tube, dimensions of the tube, and the silicone insert in the pump that regulates the device, since these are critical in achieving the ideal flow rate.

The design team started by assessing customer requirements. It then created a Design Development Plan (DDP). A customer specification was developed, and market inputs were collected. The team’s Lean focus on minimizing variability helped to cut time in these processes in several ways. First, there was a database of approved materials that have passed biocompatibility and other critical tests.

Selecting a solvent, additive, and materials that had previously passed the requisite tests cut weeks out of the development process and eliminated potential issues that could arise if a selected material had failed testing. Second, the overall design process and design tools were standardized so internal teams collaborating globally had the same frame of reference.

Once the customer specification was approved, 3D CAD models were developed and analyzed. A design review, which included functional analysis and risk evaluation, was held. After the customer’s team approved the design, prototyping and verification began.

The team used a gated design process to enable tooling development to begin as early in the design process as possible. A combination of in-house rapid prototyping capability and in-house tooling design and fabrication capability helped shorten the product development cycle by another two-to-three months. The tooling design process included a DFM phase, which was followed by development of the mold specification. Following a design review, mold fabrication began. This was followed by a testing and debugging phase, which included a dry run and analysis of product first off the tool. The KPI for this stage is no more than two-to-three tooling iterations.

Production processes underwent a similar development and validation phase with performance qualification to user requirements, operational qualification to functional requirements, installation qualification to design specification and installations.

Since this was an infusion product, testing and compliance stages included comprehensive functional testing. The device was installed in the pump and the dosing volume of a specific volume of saline was monitored for half an hour.

In this particular project, post-development interviews found that the 1.5-meter-long line was tangling. The design was modified to include a spring section, which enabled the line to be shortened and eliminated the tangling issue.

Applying Lean philosophy in the design cycle by eliminating variation through standardized systems and processes, plus vertically integrating rapid prototyping and tooling development cuts time and cost, typically reducing product development time by more than 50%. Ensuring close collaboration between the design team and manufacturing personnel ensures that the design can be commercialized optimally. Validating assumptions made in the product development cycle by measuring production efficiency and end-user ease-of-use ensures that improvement opportunities are rapidly implemented, which improves competitiveness from both cost and market share perspectives.

Several great points in this article that I would like to further expand upon and emphasize.

One is an accurate customer requirements/specifications document. Lean techniques only work well when there is an accurate, thorough and stable product requirements specification up front (i.e. a clear, stationary target to hit). This is one of the main foundations of a successful product launch.

Second is doing the necessary 'prework' or advanced development before beginning the project. As mentioned in the article, previous testing had narrowed down the critical material, solvent, and additive candidates that were to be used (instead of waiting to do this during the project and adding unnecessary time and risk to the schedule).

Finally, proper training and standardization of design tools is implemented before beginnnig the project so that everyone will hit the ground running and stay on the same page during project development.

While there are many more factors that contribute to a successful project launch, these are some of the more critical focus areas that need to be addressed at the beginning of every project.

A few weeks ago, Ford Motor Co. quietly announced that it was rolling out a new wrinkle to the powerful safety feature called stability control, adding even more lifesaving potential to a technology that has already been very successful.

It won't be too much longer and hardware design, as we used to know it, will be remembered alongside the slide rule and the Karnaugh map. You will need to move beyond those familiar bits and bytes into the new world of software centric design.

People who want to take advantage of solar energy in their homes no longer need to install a bolt-on solar-panel system atop their houses -- they can integrate solar-energy-harvesting shingles directing into an existing or new roof instead.

Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.